Do you think it's common for people who work closely together- 5 days a week, 8 hours a day- to not really know one another? I'm asking because a guy I work with had gotten married and had two kids in the past two years and the rest of us are just now finding out. He didn't even break the news either, one of the gang stumbled upon his new Facebook page and saw the picture. You could have knocked all of us over with a feather as we're pretty close. His response, after we confronted him about his secret family..."I didn't think it was any of your business."
What the heck?
I agree that the situation is a bit odd, and I can understand that you're shocked over hearing the news about your co-worker, yet I'm not surprised by his response once the word got around the office. Some people are incredibly private and like to completely separate their personal from their professional lives. It's impressive that he managed to do that for two years! Now that you know, and since he's blatantly expressed his wished to keep his business his own, keep your conversations on a professional level and leave the man be. Definitely don't take his secrecy personally as he kept his life on the down low from everyone and not just you.